What are lies? To lie is ‘to make a false statement with the intention to deceive’, according to the Oxford English Dictionary, but this might not go far enough.

Can you lie with true statements? There is a famous story about St. Athanasius, who, fleeing in disguise, was asked by his pursuers, ‘Have you seen the bishop?’ His canny but truthful response: ‘Continue: he is not far from here.’

Can you lie without statements? Suppose someone asks, ‘Have the officers stopped taking bribes?’ The speaker lies, not by stating something, but by presupposing something, i.e. that the officers have been taking bribes. Suppose a newspaper says, ‘Asylum seekers are barbecuing the Queen’s swans’. They don’t say how many asylum seekers. Some? Many? All? But it conveys a stereotype—they do that sort of thing – which is false, insulting and oppressive. (It also happened to be a straight-out lie, given that no ‘asylum seeker’ had barbecued any swan.) Sometimes you can lie, not just with what you say, but also with what you don’t say, and with what you convey through the back-door.

What, if anything, is wrong with lying? From a moral viewpoint what matters more is deception, rather than simply falsehood. And if that’s what matters, perhaps we should be concerned about other things, including the biases and omissions, the partial truths, the wider patterns of misleading speech by institutions and the media, as well as falsehoods told by individuals aiming to deceive.

Lying is, usually, wrong. Psychologists may discover that people often tell lies, especially ‘white lies’, to avoid hurting people’s feelings. There are questions about this empirical claim: the tactful euphemisms described as ‘lies’ might not be lies, if they are not intended to deceive. But in any case, the empirical claim doesn’t tell us whether lying is right or wrong. Just because people do something, doesn’t mean it is right, or even that they think it’s right.

Some philosophers have thought that lying is, not just usually, but always wrong. Immanuel Kant said it would be wrong to lie even to a would-be murderer, who comes to the door, weapon in hand, looking for the friend hidden in your house. Kant was surely mistaken in taking so hard a line. Anyone faced with evil circumstances like that should not let themselves be made a tool of evil.

Does the wrongness of lying depend on its effects? Kant thought the effects were irrelevant, but we should not lose sight of them: the undermining of trust, the damage to reputation and credibility when found out.

But in addition to these negative effects, there are also three things that make lying wrong in itself.  The first is the destruction of knowledge. Suppose you think in a bean-counting way, an economist’s way, about your speech. ‘I’ll tell the truth when that is most useful, and I’ll lie when that is most useful’.  What’s missing in this arithmetic is the value of knowledge itself. Even if you think in the bean-counting way about other people’s happiness, not just your own – ‘I’ll lie whenever it makes others happier’ – you are missing out on the value of knowledge, for its own sake, and authenticity, independently of happiness. That is what’s so bad about the prospect of ‘living a lie’, or living ‘in a fool’s paradise’.